Maybe I'll post a video. I have to figure out the best way to capture it.

To make this a little clearer, I see 4 quadrants, one for each player. I'm not sure which player is mapped to each quadrant but if player 1 is top left, 2 is top right, 3 is bottom right and 4 is bottom left as in:

1 2
4 3

What I see is players 2 and 3 are steady but the images for players 1 and 4 quadrants seem to swap quickly. You can make out the player characters properly and they seem to be moving properly/independently but the image is being swapped.

Should this be in the Game Related Discussion forum? If so, can an admin/mod please move it...

Not sure if this exactly what you are talking about. 3 and 4 player mk8 refresh only half of the screen every frame. I don’t recall the exact order but I watched it do this using a debugger. It draws the top two carts on one frame. Then the overlay stuff immediately after. Then on the next frame it draws the bottom two carts and then the overlay immediately aftwards. The the 4 quadrants are essentially running at 30 fps with frame skipping.

Like I said I don’t recall the exact order but that’s the way it works. If you aren’t getting 60 FPS constantly then this probably looks pretty bad.

Not sure if this exactly what you are talking about. 3 and 4 player mk8 refresh only half of the screen every frame. I don’t recall the exact order but I watched it do this using a debugger. It draws the top two carts on one frame. Then the overlay stuff immediately after. Then on the next frame it draws the bottom two carts and then the overlay immediately aftwards. The the 4 quadrants are essentially running at 30 fps with frame skipping.

Like I said I don’t recall the exact order but that’s the way it works. If you aren’t getting 60 FPS constantly then this probably looks pretty bad.

It's more like the wrong frames are been shown in the wrong quadrants.
So the frames from the top right corner are getting mixed in with top left corners.

So if you are 1 player, you see your own Kart/Player. But you also see player's 2 frames/Kart mixed in between (so if you look at player 1 quadrant, it looks like you are driving both player 1 and 2
Same for player 3, it sees some of player 4's frames.

Players 2 and 4 on the right hand side of the screen are not affected.